1. Field of the Invention
The present invention relates to an apparatus for reading the rows of characters of a document, and recognizing each of the characters of any row. More particularly, it relates to a character recognition apparatus for recognizing characters in accordance with the data representing sizes, positions and other attributes of the characters.
2. Description of the Related Art
A character reading apparatus for automatically reading characters from documents comprises a character recognition apparatus which recognizes each of the characters by virtue of pattern recognition techniques. The character recognition apparatus performs pattern matching processing; it compares the pattern of each character with the dictionary patterns of characters. With the character matching processing it is impossible to distinguish some capital letters from small letters, for example, "S" from "s," or "C" form "c". Consequently, the accuracy of character recognition is not sufficiently high.
A method of increasing the accuracy of character recognition is disclosed in Japanese Patent Disclosure No. 62-187088. In this method, every time the patterns of a character of each row have been recognized, the data representing horizontal reference lines are generated from the heights of the large and small of the same character, if any in the row of the characters, and the characters are sorted into several categories in accordance with their sizes, with reference to the reference lines data, thereby distinguish the large characters from the small ones.
Certainly, this method helps to enhance the accuracy of character recognition. However, since the reference line data cannot be acquired until the patterns of the characters of one row are recognized, and the patterns of the characters of any category must be compared with the dictionary patterns. Thus, the cost of the pattern matching process is just as high as in the conventional character recognition apparatuses.